Europe must beef up asteroid vigilance: ESA

Europe must strengthen its watch for dangerous asteroids, the head of the European Space Agency's asteroid surveillance program says, a week after a meteor struck Russia in a blinding fireball.

Nicolas Bobrinsky, in charge of ESA's four-year-old Space Situational Awareness (SSA) program, said his unit would inaugurate a centre in Rome on May 22 to co-ordinate observatories' sightings of passing asteroids.

A graphic representation of the Earth flyby of asteroid 2012 DA14. Photo: NASA

He called for help to build an automated network with six such telescopes so that the night sky would be scrutinised around the world.

"The fact that we are pursuing this program is very satisfying, but the take-home message is that we have to step up our efforts so that the necessary protection is put in place," Bobrinsky said.

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Such a network could give three months' warning of a dangerous asteroid, "enough to evacuate a threatened region if necessary or possibly launch a mission to change [the asteroid's] trajectory," he said.

The Chelyabinsk rock is estimated to have been 17 metres across.

It struck just hours before a 45-metre asteroid, 2012 DA 14, skimmed past the Earth at a distance of about 27,000 kilometres – the closest ever flyby by any predicted object.

Thanks to a NASA-led program, astronomers are making headway in identifying very large asteroids measuring a kilometre or more across that may stray into our neighbourhood.

"Around 99 per cent of these big asteroids have already been spotted," Bobrinsky said.

"The real danger now comes from small asteroids, which are far more numerous," he said.

About 1 million asteroids measuring 50 metres or more orbit the sun, said Bobrinsky.

How many of them are "geo-cruisers," meaning that they come close to the orbit of the Earth, is unknown. So far, fewer than 10,000 asteroids in this category have been detected, he said.

"Most of the objects that may one day pose an impact risk have not been detected," said Bobrinsky. "There is a colossal amount of work to be done."

The SSA has a 5 million euro ($6.4 million) budget throughout 2013-2016, with which it has to monitor space storms and orbital debris as well as track asteroids.